Further work will be carried out fo the isslationo the membrane proteins of the brain. By means of a highly effective protein solubilizing agent, lithium diiodosalicylate, biologically active brain glycoprteins will be purified for chemical characterization. The organ and cellular specificity of such proteins will be determined by electrophoretic and immunochemical methods. The physiological role of the prteins will be studied on neural cells under tissue culture conditions.